• Molecules and Cells
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• 제38권12호
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• pp.1096-1104
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• 2015

Particulate $matter_{2.5}$ ($PM_{2.5}$) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which $PM_{2.5}$ aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous $PM_{2.5}$ solution on lipoprotein metabolism. Collected $PM_{2.5}$ from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. $PM_{2.5}$ extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. $PM_{2.5}$ treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by $PM_{2.5}$ solution in a dose-dependent manner. Further, $PM_{2.5}$ solution caused cellular senescence in human dermal fibroblast cells. Microinjection of $PM_{2.5}$ solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of $PM_{2.5}$ induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins.

• 한국식품영양과학회지
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• 제42권12호
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• pp.1899-1907
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• 2013

복분자 미숙과 물추출물이 콜레스테롤 개선에 미치는 영향을 측정한 결과는 다음과 같다. 간세포주(HepG2 cells)에서 복분자 미숙과 물추출물은 SREBPs를 증가시킴으로써 혈액 내에 LDL을 LDL receptor를 통해서 세포 안으로 흡수시키고, 콜레스테롤 합성에 관여하는 HMG-CoA reductase 활성을 억제하면서 체내 콜레스테롤을 조절하였다. 그러나 HDL의 생성에 관여하는 유전자(ABCA1, SR-B1)는 변화를 보이지 않았다. 결과적으로 복분자 미숙과 물추출물이 LDL receptor를 통해서 LDL을 억제시키고 체내에서는 콜레스테롤 생합성을 억제하였으며, HDL의 생성에는 관여를 하지 않음을 확인하였다. 또한 ApoB1/ApoA1 ratio 값을 통해서 동맥경화 지표를 확인해 본 결과 유의성 있게 수치가 감소함을 확인하였고, 이는 미숙과 물추출물이 콜레스테롤을 개선하여 동맥경화를 예방할 것으로 기대한다. 또한 대식세포(RAW 264.7 cells)에서 복분자 미숙과 물추출물이 CD 36, SR-A 수용체를 억제시킴으로 인해 세포 내의 ox-LDL 의 흡수를 차단시키고, 세포 안에서는 macrophage에 있는 PPAR-${\gamma}$를 억제시킴으로 인해 LDL 산화가 억제되었다. Adipophilin의 활성이 억제됨에 따라 세포 안에 있는 콜레스테롤 방출을 촉진시킴으로 인해 동맥경화를 완화시킬 수 있다고 사료된다.

• Molecules and Cells
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• 제37권11호
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• pp.777-784
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• 2014

Epidemiologic studies have shown that low-density lipoprotein cholesterol (LDL-C) is a strong risk factor, whilst high-density lipoprotein cholesterol (HDL-C) reduces the risk of coronary heart disease (CHD). Therefore, strategies to manage dyslipidemia in an effort to prevent or treat CHD have primarily attempted at decreasing LDL-C and raising HDL-C levels. Cholesteryl ester transfer protein (CETP) mediates the exchange of cholesteryl ester for triglycerides between HDL and VLDL and LDL. We have published the first report indicating that a group of Japanese patients who were lacking CETP had extremely high HDL-C levels, low LDL-C levels and a low incidence of CHD. Animal studies, as well as clinical and epidemiologic evidences, have suggested that inhibition of CETP provides an effective strategy to raise HDL-C and reduce LDL-C levels. Four CETP inhibitors have substantially increased HDL-C levels in dyslipidemic patients. This review will discuss the current status and future prospects of CETP inhibitors in the treatment of CHD. At present anacetrapib by Merck and evacetrapib by Eli Lilly are under development. By 100mg of anacetrapib HDL-C increased by 138%, and LDL-C decreased by 40%. Evacetrapib 500 mg also showed dramatic 132% increase of HDL-C, while LDL-C decreased by 40%. If larger, long-term, randomized, clinical end point trials could corroborate other findings in reducing atherosclerosis, CETP inhibitors could have a significant impact in the management of dyslipidemic CHD patients. Inhibition of CETP synthesis by antisense oligonucleotide or small molecules will produce more similar conditions to human CETP deficiency and may be effective in reducing atherosclerosis and cardiovascular events. We are expecting the final data of prospective clinical trials by CETP inhibitors in 2015.

• Molecules and Cells
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• 제26권5호
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• pp.468-473
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• 2008

Low-density lipoprotein (LDL) induces cell proliferation in human aortic smooth muscle cells (hAoSMCs), which may be involved in atherogenesis and intimal hyperplasia. Recent studies have demonstrated that $Cl^-$ channels are related to vessel cell proliferation induced by a variety of stimuli. In this study, we investigated a potential role of $Cl^-$ channels in the signaling pathway of LDL effects on hAoSMC proliferation with a focus on the activation of Erk1/2-PI3K/Akt and the subsequent upregulation of Egr-1. $Cl^-$ channel blockers, DIDS, but neither NPPB nor Furosemide, completely abolished the LDL-induced DNA synthesis and cell proliferation. Moreover, DIDS, but not NPPB, significantly decreased LDL-stimulated $Cl^-$ concentration, as judged by flow cytometry analysis using MQAE as a $Cl^-$-detection dye. DIDS pretreatment completely abolished the activation of Erk1/2 and PI3K/Akt in a dose-dependent manner that is the hallmark of LDL activation, as judged by Western blot and proliferation assays. Moreover, pretreatment with DIDS ($Cl^-$ channel blockers) but not LY294002 (PI3K inhibitors) completely abolished the LDL-induced upregulation of Egr-1 to the same extent as PD98059 (MEK inhibitors to inhibit Erk), as judged by Western blot and luciferase reporter assays. This is the first report, to our knowledge, that DIDS-sensitive $Cl^-$-channels play a key role in the LDL-induced cell proliferation of hAoSMCs via the activation of Erk1/2 and PI3K/Akt and the upregulation of Egr-1.

• BMB Reports
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• 제45권8호
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• pp.464-469
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• 2012

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl.

• 동의생리병리학회지
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• 제27권2호
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• pp.189-195
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• 2013

This study was designed to analyze the effects of methanol extracts and solvent fractions of the young branch of Prunus persica on scavenging activity of ROS, RNS and inhibiting activity of oxidative modification in human LDL induced by copper ion or free radical generator. The scavenging capacities of the fractions on DPPH radical, superoxide radical, nitric oxide and peroxynitrite were exhibited the highest in ethylacetate fraction, followed by butanol fraction. In the copper-induced LDL oxidative modification system, the highest antioxidant activity was revealed in ethylacetate fraction, and butanol fraction exhibited a similar activity. However, solvent fractions of the young branch of Prunus persica showed a relatively low antioxidant activity in the AAPH-mediated LDL oxidation. In addition, ethylacetate and butanol fractions also inhibited the copper-mediated LDL oxidation in the REM assay, which was comparable to that of the positive controls, including EDTA, ascorbic acid and BHT. Futhermore, a content of total phenolics in these two fractions was higher than that of the other fractions. These results indicated that ethylacetate and butanol fractions of the young branch of Prunus persica were useful for the prevention of the free radical- or metal ion-induced oxidative damages.

• Journal of Ginseng Research
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• 제28권2호
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• pp.87-93
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• 2004

인삼성분 중 ginsenoside-Rb$_2$에 의한 LDL receptor발현 증가의 기전을 HepG$_2$세포에서 관찰하였고 이를 lovastatin과 비교하였다. 콜레스테롤 투여에 의하여 억제된 LDL receptor mRNA발현이 ginsenoside-Rb$_2$에 의하여 다시 증가하였고 이는 lovastatin에 의한 증가 효과보다 뛰어났다. SREBP mRNA의 발현 또한 콜레스테롤 투여에 의하여 억제되나 ginseonside-Rb$_2$에 의하여 발현이 증가하였고 이는 lovastatin에 의한 효과와 비슷하였다. 세포에 투여한 ginsenoside-Rb$_2$의 농도에 비례하여 SREBP-1 mRNA의 발현이 증가하였으며 ginsenoside-Rb$_2$의 대사체인 compound K를 투여한 경우에도 SREBP-1 mRNA가 비슷한 양상으로 혹은 더 많이 발현되었다. 따라서 ginsenoside-Rb$_2$에 의한 LDL receptor의 발현 증가는 SREBP의 발현 증가 때문이라고 설명할 수 있다. 즉 ginsenoside-Rb$_2$에 의한 SREBP 발현 증가는 콜레스테롤 투여에 의하여 억제된 LDL receptor발현을 증가시켜 결과적으로 혈중의 콜레스테롤을 효과적으로 제거하는 것으로 판단된다.

• BMB Reports
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• 제34권4호
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• pp.329-333
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• 2001

Active lipoprotein lipase (LPL) is known as a noncovalent homodimer of identical subunits, and dissociation of the dimer to a monomeric form renders the lipase inactive. In this study, the oligomerization status of LPL in human and rat plasma was investigated. The LPL activity was barely detectable in the control rat and human plasma. After the injection of heparin, the total lipolytic activity of plasma was rapidly increased, and reached its maximum in 30 min. Changes of the LPL protein correlated well with those of lipolytic activity. The LPL protein that is released by heparin into both human and rat plasma was active and dimeric in the sucrose density gradient ultracentrifugation. In control rat plasma, LPL was inactive, and a great fraction was present as an aggregate. However, the inactive LPL protein in the control human plasma retained the dimeric state, indicating that dimerization can be an entity independent of the catalytic activity of LPL. The released LPL is transported as a complex with lipoproteins in plasma. Lipoprotein profiles, determined by NaBr ultracentrifugation, exhibited typical LDL- and HDL-mammal patterns in humans and rats, respectively, with a smaller amount of the LDL fraction observed in rats. The difference in the lipoprotein profiles might influence the fate of the released LPL in plasma.

• 한국식품위생안전성학회지
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• 제21권4호
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• pp.213-217
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• 2006

비브리오 불니피쿠스는 우리의 식생활과 밀접한 관계가 있는 어패류와 바닷물에 의해 간경화 같은 만성 간질환 환자에 주로 감염되어 높은 치사율을 보이는 비브리오. 패혈증을 일으킨다. 그러나 현재까지도 항생제 같은 대증적 요법 외 효과적인 치료 및 예방 방법이 없는 실정이다. 최근 혈중 LDL같은 지단백질 이 감염 과 염증반응에 중요한 방어작용을 가지고 있음이 알려졌다. 따라서 LDL이 비브리오 패혈증에 영향을 미치는지 평가해 보았다. 비브리오 패혈증을 일으키는 비브리오 불니피쿠스 균을 배양하고, 대표적인 병태 인자인 비브리오 불니피쿠스 cytolysin를 추출하여 cytolysin의 용혈 활성에 혈청, 콜레스테롤 및 LDL의 영향을 조사하였다. 그리고 마우스에 직접 LDL를 복강 내 주입하여 혈중농도를 변화시킨 후 비브리오 불니피쿠스 균의 마우스 사망률을 조사하였다. 또한 전북 지역 대학 병원에서 비브리오 패혈증 환자에서 생존한 환자와 사망한 환자의 콜레스테롤과 LDL를 조사하였다. 비브리오 불니피쿠스 cytolysin의 용혈 활성은 혈청, cholesterol 및 LDL에 의해 억제되었다. 비브리오 불니피쿠스 균의 마우스 사망률은 LDL을 주입한 경우 40%나 사망률이 낮게 나타났다. 전북 지역 대학 병원에 비브리오 패혈증으로 입원 중인 환자 (15명)의 혈액 분석에서 정상 수준의 콜레스테롤 $(190.8{\pm}16.3)$과 혈청 지단백질 LDL $(53.3{\pm}40.7)$을 가진 환자는 모두 생존하였다 (4명). 그러나 정상보다 낮은 수치 ($35.6{\pm}13.9,\;LDL;\;59.2{\pm}15.1$, 콜레스테롤)를 보이는 환자는 사망하였다 (11명). 콜레스테롤과 LDL은 비브리오 불니피쿠스 cytolysin의 독작용의 억제 요소로서, 비브리오 패혈증의 예후에 중요한 요소임이 밝혀졌다. 또한 이는 콜레스테롤과 LDL이 비브리오 패혈증의 예방과 치료에 중요한 지표가 될 수 있음을 시사한다.

• 약학회지
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• 제48권4호
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• pp.236-240
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• 2004

Acanthopanax species (Araliaceae) traditionally has been used as analgesics, stimulant of immune system, and replenishment of body functions. Acanthopanax divaricatus var. albeofructus is indigenous plant to Korea. The antioxidant activities of compounds from A divaricatus var. albeofructus were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and thiobarbituric acid reactive substance (TBARS) assay on human plasma low-density lipoprotein (LDL). The triterpenoid and lignan constituents from this plant showed antioxidant activities and the lignan, l-sesamin exhibited the most potent antioxidant activity in Cu$^{2+}$ -induced LDL oxidation.n.